Growing Cannas
Your order will contain canna/s sold as bare root rhizomes. Each rhizome has several nodes on it. Note each variety of canna can have quite different rhizome shapes and sizes. Some grow as clusters, some as thick tubers, others in separated groups of nodes. It is important to plant your new fresh rhizomes with the growth nodes pointing upwards covered with at least 5-8cm of soil and kept damp until plants are actively growing and developing new leaf. With warm weather, the nodes on the rhizome will begin to shoot and will pop up through the soil and develop into leaf and stem.
Site and Soil
Cannas do well in most soil types – sandy, loam and clay however they thrive best in moist soils and/or when mulched. A position in full sun is best, cannas will tolerate partial shade but flowering will be less. Choose a site with at least four or five hours of direct sunlight in summer and you won’t go too far wrong. Cannas are strongly free standing but are best sheltered from the wind by planting them near a wall or the side of the house as they will flower longer and better with some protection.
When to plant
Cannas can be planted all year round.The very best times of the year are September to March when they will start growing almost from the time you plant them. Late autumn and winter is also fine but growth will be slow until warm weather returns. In deep heavy winter frost areas, newly planted rhizomes are best mulched or covered till the warmer weather arrives. If a heavy frost should burn the new fresh tips in late winter the base of the nodes which are buried below the surface will still continue to develop and shoot. These plants are great survivors and are extremely hardy here we grow them all with our minimum winter temps of -8c and our maximum summer temps of 45c.
How to Care for Cannas
After planting rhizomes, fertilizer can be applied when new fresh stems have grown approximately 30cm high and again say a month later. Cannas are not fertilizer specific. Aquasol, Thrive etc will be fine if you follow the directions on the packet. Please don’t fertilize too much or you may have a lot of leaf at the expense of flowers. Here we only fertilize once a year we use 9 month osmocote when planting new rhizomes. With care and a little fertilizer, water and warm weather, you can expect a nice plant with flowers within 8-12 weeks. For a longer display of flowers on established plants, spent flowering stems can be cut near the base and removed to allow new stems to develop and flower.
Pests and Diseases
Cannas are pest and disease free and once established, and are very hardy to drought conditions. No mites or aphids beetles grasshoppers fungus mildews. The only problem we have here are slugs and snails can be attracted to fresh new shoots from newly planted rhizomes which is pretty easy for us to deal with, so it is wise to keep an eye out. Once the shoots turn to leaf and the plants establish they no longer seem interested.